Simulated Moving Bed Chromatography Purification Of Mung Bean Dregs-resistant Dextrin And Its Characteristics

Resistant dextrin is a kind of water-soluble dietary fiber with the functions of regulating blood glucose,regulating intestinal flora,reducing blood lipid and weight loss.Mung bean residue is the by-product of mung bean vermicelli,mung bean starch,mung bean protein and other products.It contains a variety of functional components,but it is usually used as feed or directly discarded as waste,resulting in a great waste of resources and environmental pollution.In this context,in order to improve the utilization rate and added value of mung bean residue,mung bean residue resistant dextrin was prepared by microwave enzymatic method with mung bean residue as raw material.It was purified by simulated moving bed chromatography.Finally,its physicochemical structure was analyzed by scanning electron microscopy,infrared spectroscopy,X-ray diffraction,differential refractive index detection and gas chromatography-mass spectrometry,Its in vitro digestibility,in vitro hypoglycemic effect,in vitro lipid-lowering and other functional properties were analyzed.The results show that:(1)The optimum technological parameters of microwave enzymatic preparation of resistant dextrin were as follows: microwave time 13 min,microwave power 582 W,hydrochloric acid dosage 8%,hydrochloric acid concentration 1%,high temperature resistant α-amylase dosage 0.5%,starch glucosidase dosage 0.5%,mung bean resistant dextrin content 54.82%.(2)The results showed that the optimum conditions of single column chromatography were as follows: feed concentration 60%,column temperature 60 ℃,elution flow rate 1.60 ml / min;the optimum process parameters of simulated moving bed chromatography were as follows: feed volume 455 g / h,water inflow 682 g / h,circulation volume 346 ml,the purity of mung bean resistant dextrin was 99.17%.(3)Physicochemical properties of mung bean resistant dextrin: compared with starch,the solubility and water holding capacity of mung bean resistant dextrin are significantly improved;its particle size is different and the surface is rough,which is irregular and amorphous structure;compared with mung bean starch,the corresponding chemical bond content and types of mung bean starch changed significantly;its crystallinity is not high,which is amorphous;its molecular weight is relatively concentrated,which is amorphous The radius of gyration was(279.40 ± 11.70)nm.The monosaccharide groups were glucose,arabinose and xylose.(4)Functional characteristics of mung bean resistant dextrin: the content of resistant starch was 91.14% and 97.85% by simulated digestion of gastrointestinal juice and simulated enzymatic hydrolysis in vitro,respectively,which was significantly higher than that of starch;the inhibition effect of mung bean resistant dextrin on α-glucosidase and α-amylase activity was weaker than that of acarbose,and the inhibition effect was positively correlated with the concentration;it had good adsorption effect on sodium cholate solution,and the content of bile salt was lower than that of acarbose When the concentration was higher,the adsorption effect was better;the adsorption rates of cholesterol were 28.12% and 22.50% at p H7.0 and p H2.0,respectively,and the adsorption effect was better under neutral conditions;the adsorption capacity of lard and soybean oil was higher than that of starch;the adsorption effect of nitrite was worse than that of mung bean starch.